Tesla’s senior vice president of engineering, Doug Field, is leaving the company for good after previously stepping away for what the company had characterized as a leave of absence.

Tesla confirmed his departure and said:

“After almost five years at Tesla, Doug Field is moving on. We’d like to thank Doug for his hard work over the years and for everything he has done for Tesla.”

The Wall Street Journal first reported his departure.

Field, who was formerly a VP of hardware engineering at Apple, joined Tesla in 2013. He was responsible for development of new vehicles there, including the Model 3 electric sedan, which is the company’s first EV designed for the mass market.

Tesla’s future hinges on efficient, high-volume production of the Model 3. But the company has so far failed to hit its production goals for the vehicle and has yet to release the $35,000 base model of the car to eager drivers.

In early April, Musk announced that he would personally take over responsibilities for Model 3 production at Tesla from Doug Field.